This is an interesting spot from the wilds of Scandinavian winter testing: another mule for an upcoming Porsche Cayenne Coupe being plotted in Zuffenhausen.

And the tale becomes more interesting. We know that Porsche is considering a coupe-ified, lower crossover to match the likes of the Mercedes-Benz GLE Coupe, BMW X6 and other slammed SUVs.

But it's also electric-powered, according to our sources. As evidenced by the EV stickers on this engineering prototype.

It crept silently past our spy photographer, suggesting it is either a full electric SUV or a hybrid running in saintly EV mode.

Whichever powertrain, it's proof that Porsche is preparing to challenge the growing number of crossover EVs being developed by the world's premium car makers, desperate to remove the stigma from super-sizing their cars.

Porsche Cayenne Coupe: an electric testbed

CAR's insiders at Porsche tell us the car is not yet approved for production, but this long-distance sighting of a test car mule wrapping a Panamera body on SUV running gear suggests the project is forging ahead.

We hear that this hack is an electric version twinned with the forthcoming Audi E-tron. It's not the first time we've spied it; in summer 2016, our spy photos captured it undergoing braking tests in Germany, as they refined the regenerative set-up.

Gas guzzlers? An SUV re-volt, more like...

Indeed. Watch out for this growing trend. Tired of SUVs being slated as the devil's spawn, car makers are working furiously to clean up the act of their premium 4x4s.

It's no surprise: this is the point at which two market trends - electrification and the rise of the SUV - collide. Electric 4x4s are seemingly The Next Big Thing.